In the bowl of a stand mixer, cut the butter into the flour with a knife or pastry cutter, then rub in with your fingertips. Add the confectioners' sugar to the butter and flour. Mix the yeast with the water and sugar. Let stand briefly to activate.
Add the dissolved yeast, eggs, egg yolks, sour cream, vanilla and lemon rind to the flour mixture. Using the dough hook attachment, knead the dough for 5 to 8 minutes until it is smooth and elastic.
Lightly oil a large bowl. Place the dough in the oiled bowl, cover, and set aside in a draft-free place to rise until doubled. It should take about 2 hours. During that time, you can make the filling.
Simmer the poppy seeds in a pot of water (enough to cover) until soft, about 40 minutes, stirring frequently.
Drain the poppy seeds, using a very fine sieve. Press as much water as you can from the seeds. Spread the seeds in a thin layer on paper towels and set aside to allow excess moisture to evaporate.
Grind the poppy seeds in a food processor for about 4 minutes. Add the almonds and grind for a few seconds.
Melt the butter in a saucepan or skillet. Add the poppy seed mixture, sugar, raisins, vanilla, honey, candied orange rind and grated lemon rind. Cook over medium-low heat for 10 minutes. Transfer to a bowl and cool slightly. Add the beaten egg.
In another bowl, whip the egg whites until stiff peaks form. Fold into the filling mixture. Let cool.
After 2 hours, when the dough has doubled, punch it down. Knead it briefly, then divide the dough into 4 equal parts. Roll each piece into a rectangle. Spread each rectangle with an equal amount of filling, leaving a 1-inch margin from each edge. Starting at the long end, roll the dough into a log and seal the ends.
With the seam side down, place the rolls on a nonstick or greased cookie sheet.
Place the rolls in a warm oven to rise. Let stand until the rolls double in size, about 1 hour.
Preheat the oven to 350 degrees F.
If using the glaze, brush the rolls with milk and sprinkle with poppy seeds before baking.
Bake the rolls for 30 minutes. Cool. The rolls may be served as-is from the oven, or decorated using either the icing or the glaze.
To make the icing: Mix the confectioners' sugar and lemon juice. Spread on the rolls and decorate with candied orange rind.
To make the glaze: Heat the preserves and lemon juice on medium-high until bubbling. Pour the mixture through a fine sieve to remove any remaining fruit pieces, reserving the liquid. Stir the rum into the liquid. Brush the glaze over the rolls and scatter almonds on top.
Put the orange peels in a saucepan with enough cold water to cover. Boil for 10 minutes, then drain. Cover again with cold water and repeat the cycle 2 more times. Drain the rinds and rinse with cold water. Scrape off the pithy, white part of the rind and cut the rind into very thin strips.
Measure the volume of orange rind strips. For each cup of rind, in a saucepan prepare a sugar syrup of 1 cup sugar and 1 cup water.
Add the rind strips to the syrup. Cook low and slow until the syrup is completely absorbed. Be patient. This process takes several hours. Stir the mixture occasionally. Be vigilant near the end of the process to prevent burning.
Cool the rind strips on wax or parchment paper. Coat the strips with granulated sugar. Dry strips overnight on a rack. The sugared peel will keep for several months in an airtight container.
Recipe courtesy of Polish Classic Desserts by Laura and Peter Zeranski (Pelican Publishing, 2013)